Contrasty negs = overexposure / overdevelopment?

Messages
462
Name
Dave
Edit My Images
Yes
I am playing with a small stock of Foma Classic 100 and Kentmere Pan100, developing in Ilfosol3.
It's early days yet, the Foma was used to test a few old cameras and is only now being used in cameras/metering that I can have some confidence in.

In the small number of rolls that I've developed so far, the Foma does seem to give more contrasty negatives than the Kentmere Pan100.

Can the contrast be lowered by underdevelopment or underexposure?
 
Contrast is determined by development. More development = more contrast.
Density is determined by exposure. More exposure = more density.

One of the earlier editions of one of Michael Langford's books had the best illustrations I've seen of this. A contrasty subject, a series of photos of the negatives with varying exposure, fixed development, and the reverse. Summing up - after about 4 mins development, shadows remained the same, and highlights got darker and darker (= higher contrast).
 
How are you making your prints?

If via scanning negatives, lower contrast makes things easier.

If in a darkroom, development should be tailored to enlarger illumination. You'll find makers give different times for condenser and diffuser enlargers - or they used to...

Edit to add:

For the sake of completeness, there is one other contrast variable. If reciprocity effects kick in, at the long end of the exposure scale, contrast goes up, and at the short end, down. Depending on the film, you're OK in the 1/2 to 1/1000th range.
 
Last edited:
Thanks for your posts. Only negs for scanning. My wet printing days ended some years ago.
 
Can the contrast be lowered by underdevelopment or underexposure?
Stephen has a lot more experience than me, but from my limited testing, pulling the film (over expose and under develop) offers some reduction in contrast. Not so much in the highlights, but in retaining a bit more shadow detail.

Also, not sure how you are scanning, but certainly with Silverfast I have a significant degree of control over the scan contrast. Sadly it can't create what isn't there, so pulling the film will give you a bit more of an option. Much easier to add contrast in PP than take it away (again - in my limited opinion!)
 
ML's illustrations make the same point, but Prof. Agar adds prints as well, which emphasise the point.

I always overexpose according to the makers, because the penalties of doing so don't affect me, whereas the penalties of underexposure do.

The late Barry Thornton said that virtually everyone overdeveloped their films, and should knock at least 15% off the times.
 
P.S. Ian's experience with scanning matches mine. Lower contrast negatives give better scans.
 
P.S. Ian's experience with scanning matches mine. Lower contrast negatives give better scans.
With the risk of more visible grain if the contrast range is expanded in PP?
 
Possibly. But as I don't use 35mm, very rarely use medium format and prefer 5x7 to 5x4, grain isn't an issue for me. It's certainly worth bearing that in mind in reading any advice I offer.

Extra exposure does increase grain and reduce resolution/sharpness, but that isn't a problem for me. My print sizes from large format are equivalent to 6"x4" from 35mm, which isn't enough to show a lot of faults.
 
Last edited:
How are you making your prints?

If via scanning negatives, lower contrast makes things easier.

If in a darkroom, development should be taylored to enlarger illumination. You'll find makers give different times for condenser and diffuaer enlargers - or they used to...

This is such an important point and incredibly well summarised Stephen

So many of the 'true film ISO vs EI' discussions on the internet focus on negatives needed for condenser head and darkroom printing. In my experience however those negatives will be less than ideal for any other usage of the negative.

It's not uncommon for people to aim for a CI/gamma around the .52 mark if condenser head enlargement is the aim. Very few manufacturers, though, indicate ISO at .52, with many instead using anything from .6 to .7 as a target gamma (Foma and Agfa come to mind).

Also, many new film users scan. One perhaps unintended result of aiming for a target gamma of .5-6 is that those scanning their negative (ill advised by those who only print) end up with the unmistakeable signature of a dense 'condenser-head' negative, which usually means a sub-optimal scan.
 
Edit to add:

For the sake of completeness, there is one other contrast variable. If reciprocity effects kick in, at the long end of the exposure scale, contrast goes up, and at the short end, down. Depending on the film, you're OK in the 1/2 to 1/1000th range.

And for the sake of completeness, something else to add that affects contrast for some of us, although from the reference to rolls of film, not OP. The lens used.

I was reading up on the Dagor lens this week. If not a large format photographer, or not interested in the history of lens design, you won't have heard the name. It goes back to the 1890s and was still in production in the 1960s. It was therefore made before lens coating was developed, and earlier examples were uncoated. Having very few air to glass surfaces, it still provided plenty of contrast at a time when more air to glass surfaces meant low(er) contrast.

Paul Strand, a photographer who influenced Ansel Adams, had one of his uncoated lenses coated. The result was higher contrast, and he said that he had to reduce his development times by 25% to compensate.

General levels of flare have the effect of disproportionately lifting the light in the shadows, reducing contrast. An efficient lens hood can therefore increase contrast as well as other factors that can reduce flare which are down to the camera makers.
 
Last edited:
Back
Top